Try-square



(No Model.) 'I

W. JOHNSON.

TRY SQUARE.

Patented Eff/9%- --zb 'o A '0 p 'o '0 Wl M22.

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UNITED STATES WILLIAM JOHNSON, .OF

HULL, MASSACHUSETTS.

TRY-SQUARE.

SPECIFICATION forming part of Letters Patent No. 496,227, dated April 25, 1893.

Application tiled June 20, 1892. Serial No. 437,309. (Ne model.)

To all whom it may concern: j

` Be it known that I, WILLIAM JOHNSON, of Hull, in the county of Plymouth, State of Massachusetts,have invented certain new and useful Improvements inv Try-Squares, of which the following is a description sufticiently full, clear, and exact to enable any person skilled in the art or science to which said invention appertains to make and use the same, reference lbeing had to the accompanying drawings, forming part of this specification, in which- Figure l is a sideelevation partly in vertical longitudinal section of Iny improved trysquare. Fig. 2 is a vertical longitudinal section of the same, the marking ngers or teeth being represented as projected. Fig. 3 is an end elevation of the same partly in section; Fig. 4.a plan View of the cap-plate; Fig. 5 a top plan view showing the marking teeth housed; and Fig.' 6 a like View Showing the teeth projected.

Like letters and figures of reference indilcate corresponding parts in the different iigdinarily employed, it being designed particularly as an improvement on the device shown in'my Letters Patent dated December 1, 1891, No. 464,407. i -Y In the drawings, AVB represent the arms of my improved self-*marking try-square, said arms being arranged at right-anglesto each other in the ordinary manner and the marking arm, B, being thinner than the companion arm, A, for the purpose of forming a shoulder for engagingthe edge of the stock. The markin the bottom of the' chamber, d, in parallelism.;n The ends lot" said levers project into the upper y portion of". the framab, and are bent forming a head, j. Said levers liare laterally at, q, to form a hole for the fingers in operating the square. ,l

The arm, B, is hollow and is formed from metallic plates'said arm being let into the frame, b, centrally and at right-angles thereto and secured therein.by screws, m, passing through lugs, p, in said frame. The levers, h, are thus disposed on opposite Sides of the arm, B, and their off-set portions, q, are exposed on the open portion of the frame, b. Pivoted to a lug, r, in the bottom of the frame there is a vertical lever, t, pushed outward by a spring, o., The levers, h, are connected within the chamber, d, by a'cam-shaped block, w, against which the lever, t, is4 held by the spring, o. The outer edge of the arm, B, ris open at, fr, and is adapted 'to be closed by a face-plate, y,"said face-plate is mounted on two angular vertically arranged plates, e', at each end. Said plates, s, project into a'chamber, 15, formed within the arm, B, and pushsprings, 16, tend to force said angle-platesinward whereby the face plate, y, is normally held fiush with the edge of the arm, B. The sliding block, C, is arranged to move longitudinally within the arm, B. Said block is provided with twocam grooves, 17, in which studs or pins, 18, connecting the Walls of the arm, B, work. The cam-grooves are so shaped that when the block, C, is moved longitudinally ofthe arm 'a' vertical motion is imparted thereto. ,The free end of the lever, t, is con- Iined by a pin, 1`9,in the inner end of the block, O.- Thesp'ring, @,-bearing again'stsaid spring tendsto'hold'saidblock'housed. When' viewed in the drawings, the lever, t, is actuated thereby drawing the block, C, in corresponding direction'.l

The block, C, is provided on its upper edge a cap-plate, D, shown in under side plan View in Fig. 4, is secured by screws. This plate between each of the studs is provided with pendent inwardly curved lips or flanges,22. A bar, H, is fitted with openings,25, (see Figs. 5 and 6) in which the studs,f20, slide. In the partitions,- 26, between said openings two horizontally swinging arms, 27, are mounted.

' the levers, h, are moved from left to right as i with a series of studs, 20, t0 the top offwhich These arms are normally in parallelism, as shown in Fig. 5, and on their outer ends are provided with marking teeth, 2S, best shown in Fig. 6. The free ends of said arms flare or are rounded slightly, as shown in Fig. 5, and the studs, 20, are V-shaped to spread said arms when the block, C, is moved. Said block is recessed vertically at, 29, and lugs, 30, on the bar, H, projects into said recess, a push spring, 31, being interposed between said lug and the vertical Wall of said recess.

On the forward or outer end of the block, C, there is an adjustable stop, 32, which engages a Wall of the chamber, 15, and limits the forward movement of said block. A stoppin, 33, (see Fig. l) limits the forward movement of the bar, I-I.

On the inner rear face of the frame, A, an adjustable T-shaped gage, J, is mounted by means of a set screw, 35, said gage being slotted longitudinally of its shank at, 36, to receive said screw.

In the use of my improvement the try-square is manipulated in the ordinary manner in obtaining the line at which to out the stock. Instead of using an aw] or pencil to mark the line a lever, 7L, the handle portion, q, of which is exposed in the frame, is thrown backward into the position shown by dotted lines in Fig. 2, carrying with it the lever, t. This moves the block, C, in corresponding direction longitudinally of the arm, B. Conjointly therewith the shape of the cam-grooves, 17, causes said block, C, to move outward from the arm. The springpushed face plate, y, is forced upward thereby compressing the springs, as shown in Fig. 2. The marking arms, 27, are thus disposed slightly above the edge of the arm, B. The iirst upward movement of the block, C, causes its lugs, 30, to slide freely in the slots, 25, of the bar, H, said lugs being V-shaped as described enter between the marking arms, 27, tendin g to spread said arms and the bar is carried backward with said block. The marking pins, 28, on said arms are thus projected over the edges of the square-arm, B, as shown in Fig. 6, and enter the stock against which said arm is laid indenting a straight line therein. As soon as the lever handle, q, is released by the hand of the operator the spring, o, throws the lever, t, backward and with it the block, C.

` Said block carrying the plate, D, the curved flanges, 22, on said plate engage the marking arms, 27, at their pivot end closing them as they leave the cam studs, 20. The bar, II, is arrested by the stop, 33, and the tension spring, 3l, is compressed as the block, C, reaches its forward limit of motion. The force of said spring is suiiicient only to hold the bar, II, so that the cam studs, 20, may spread its marking arms in the iirst movement of said block. The spring actuated lugs, e', as soon as the block, C, is housed return the face-plate, y, leavlng a smooth edge to the try-square.

The T-shaped gage, J, is

employed in positions where a long piece of stock has to be fitted into an opening and it is impracticable to adj ust the frame, A, against a wall of said opening.

Having thus explained my invention, what I claim isl. In a self-marking try-square the combination of a hollow cross-arm; a sliding block therein; a spring-pushed lever exposed in the companion squarearm for actuating said block; mechanism for projecting said block from the cross-arm when actuated by said lever; and marking arms adapted to be spread by said block into contact with the stock, substantially as described.

2. In a self-marking try-square the combination of a hollow cross-arm; a sliding block therein; a spring-pushed lever exposed in the companion square-arm for actuating said block; cams for projecting said block from the cross-arm when actuated by said lever; and marking arms adapted to` be spread by said block into contact with the stock, substantially as described.

3. In a self-marking try-square the combination of a hollow crossarm; a sliding block therein; a spring-pushed lever exposed in the companion square-arm for actuating said block 5 cams for `projecting said block from the cross-arm when actuated by said lever; and marking-arms adapted to be spread by said block into contact with the stock, and mechanism for housing said block when released, substantially as described.

4. In a self-marking try-square, the hollow cross-arm and lever-actuated block in combination with the spring-tensioned sliding-bar; pivoted marking-arms thereon; and mechanism for spreading said arms, substantially as described.

5. In a self-marking trysquare,the leveractuated block in combination with camsfor imparting vertical movement to said block; a spring-tensioned bar carriedby said block, marking arms on said bar; a spreader for said arms and mechanism for closing said arms when the block is released, substantially as described. Y

6. In a self-marking trysquare, the hollow cross-arm and spring-tensioned plate, y, in combination with the lever actuated calnguided block; a springtensioned bar carried by said block; pivoted marking arms on said bar; a spreader for said arms and the iianged plate on said block for closing said arms, substantially as described.

7. In a self-marking try-square, the forked lever, 7L, and spring-pushed lever, t, in combination with the cam-guided block, C, actuated by said lever; the cap-p1ate, D, on said block; the spring-pushed bar, II, carried by the block; laterally swinging marking points on said bar; spreaders for said points on the block; and anges on said cap-plate for closing said arms, substantially as described.

8. In a seltmarking tr -square, the hollow IOO the spring-pushed lever in operative' connection with said block, substantially as set forth.

' WILLIAM JOHNSON.

Witnesses:

O. M. SHAW, K. DURFEE. 

